Various kinds of instruments, appliances, etc., used at hospitals, laboratories, etc., are sterilized for disinfection. Typical sterilization treatment procedures include a sterilization treatment using hydrogen peroxide gas.
In this sterilization treatment, an indicator needs to be installed to confirm whether the sterilization treatment is complete. In more detail, it is necessary to install, in a sterilizer, an indicator whose color changes in response to the atmospheric gas concentration in a processing system and to the exposure time.
As a prior-art technique for such an indicator, known is, for example, a method in which the progress of sterilization is detected when an indicator using bromophenol blue, which is a pH indicator, turns from light blue to dark blue due to the action of peracetic acid or acetic acid gas when monitoring a sterilizing process in, for example, low-temperature gas plasma sterilization using gas comprising peracetic acid and acetic acid as principal components, (Patent-Document 1).
Further, an indicator for use in plasma sterilization which comprises a coloring matter, a color changing auxiliary, and a binder and which exhibits change in the color tone due to plasma sterilization is known (Patent Documents 2 and 3).
Furthermore, an ink composition for detecting plasma sterilization comprising an anthraquinone-based dye having at least one amino group selected from a primary amino group and a secondary amino group is known (Patent Document 4).
[Patent Document 1] U.S. Pat. No. 5,482,684
[Patent Document 2] Japanese Unexamined Patent Publication No. 1999-178904
[Patent Document 3] Japanese Unexamined Patent Publication No. 2002-11081
[Patent Document 4] Japanese Unexamined Patent Publication No. 2001-174449